Research on Speed Sensorless Vector Control System of Asynchronous Motor Based on MRAS

Abstract

This paper analysed the basic principle of speed sensorless vector control system. Based on speed and current closed loop vector control, combined with a simple and feasible current hysteresis control strategy, the whole speed sensorless system of asynchronous motor is simulated in MATLAB/Simulink. The method uses the Model Reference Adaptive System (MRAS). The observation and analysis of waveform shows that the system has good static performance and robustness. The control effects are also as similar as the vector control system which contains speed sensor.

Speed Identification Method of Induction Motor Based on Improved MRAS

“…The accuracy of the rotor flux based MRAS speed observer [8] depends on the matching degree of rotor flux observer and the actual rotor flux of motor.…”

“…Therefore, the model-based methods and especially MRAS-based methods are the most widely used until now due to its simplicity. proposed by Schauder [8], still remain the most widely used methods, and did a number of studies to improve its performance. Indeed, the disadvantages of this method are parameter (especially the stator resistance) sensitivity and pure integration problems limit the motor performance at low and zero speed region.…”